Annotation Part of the What is..? series, this book is an introductory guide providing explanations of the nature of social network methods. This volume in the 'What is..?' series will draw on presentations given at the ESRC Festival of Research Methods, but will amplify those presentations through extended examples and illustrations. Social networks operate on many levels, from families up to the level of nations, and they play a critical role in determining the way problems are solved, organizations are run, and the degree to which individuals achieve their goals. Social network theory maps these relationships (ties) between individual actors (nodes). The resulting graph-based structures are often very complex. Though relatively new on the scene it has become hugely influential across the social sciences. The book will be aimed at novice users and those contemplating the use of social network analysis in their research and so will not aim to be a detailed handbook. It will instead be an introductory guide that outlines and explains the nature and purpose of social network methods.